Home | History | Annotate | Line # | Download | only in dev
gpiic_opb.c revision 1.1
      1 /*	$NetBSD: gpiic_opb.c,v 1.1 2003/10/06 16:15:46 scw Exp $	*/
      2 
      3 /*
      4  * Copyright 2002, 2003 Wasabi Systems, Inc.
      5  * All rights reserved.
      6  *
      7  * Written by Steve C. Woodford for Wasabi Systems, Inc.
      8  *
      9  * Redistribution and use in source and binary forms, with or without
     10  * modification, are permitted provided that the following conditions
     11  * are met:
     12  * 1. Redistributions of source code must retain the above copyright
     13  *    notice, this list of conditions and the following disclaimer.
     14  * 2. Redistributions in binary form must reproduce the above copyright
     15  *    notice, this list of conditions and the following disclaimer in the
     16  *    documentation and/or other materials provided with the distribution.
     17  * 3. All advertising materials mentioning features or use of this software
     18  *    must display the following acknowledgement:
     19  *      This product includes software developed for the NetBSD Project by
     20  *      Wasabi Systems, Inc.
     21  * 4. The name of Wasabi Systems, Inc. may not be used to endorse
     22  *    or promote products derived from this software without specific prior
     23  *    written permission.
     24  *
     25  * THIS SOFTWARE IS PROVIDED BY WASABI SYSTEMS, INC. ``AS IS'' AND
     26  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
     27  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     28  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL WASABI SYSTEMS, INC
     29  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
     30  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
     31  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
     32  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
     33  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     34  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
     35  * POSSIBILITY OF SUCH DAMAGE.
     36  */
     37 
     38 #include "locators.h"
     39 
     40 #include <sys/param.h>
     41 #include <sys/systm.h>
     42 #include <sys/device.h>
     43 #include <sys/errno.h>
     44 #include <sys/lock.h>
     45 
     46 #include <machine/cpu.h>
     47 
     48 #include <dev/wasabi_i2c/i2cvar.h>
     49 #include <dev/wasabi_i2c/i2c_bitbang.h>
     50 
     51 #include <powerpc/ibm4xx/dev/opbvar.h>
     52 #include <powerpc/ibm4xx/dev/gpiicreg.h>
     53 
     54 struct gpiic_softc {
     55 	struct device sc_dev;
     56 	bus_space_tag_t sc_bust;
     57 	bus_space_handle_t sc_bush;
     58 	uint8_t sc_txen;
     59 	struct i2c_controller sc_i2c;
     60 	struct i2c_bitbang_ops sc_bops;
     61 	struct lock sc_buslock;
     62 };
     63 
     64 static int	gpiic_match(struct device *, struct cfdata *, void *);
     65 static void	gpiic_attach(struct device *, struct device *, void *);
     66 
     67 CFATTACH_DECL(gpiic, sizeof(struct gpiic_softc),
     68     gpiic_match, gpiic_attach, NULL, NULL);
     69 
     70 static int	gpiic_acquire_bus(void *, int);
     71 static void	gpiic_release_bus(void *, int);
     72 static int	gpiic_send_start(void *, int);
     73 static int	gpiic_send_stop(void *, int);
     74 static int	gpiic_initiate_xfer(void *, i2c_addr_t, int);
     75 static int	gpiic_read_byte(void *, uint8_t *, int);
     76 static int	gpiic_write_byte(void *, uint8_t, int);
     77 static void	gpiic_set_dir(void *, uint32_t);
     78 static void	gpiic_set_bits(void *, uint32_t);
     79 static uint32_t	gpiic_read_bits(void *);
     80 
     81 static int
     82 gpiic_match(struct device *parent, struct cfdata *cf, void *args)
     83 {
     84 	struct opb_attach_args *oaa = args;
     85 
     86 	if (strcmp(oaa->opb_name, cf->cf_name) != 0)
     87 		return 0;
     88 
     89 	return (1);
     90 }
     91 
     92 static void
     93 gpiic_attach(struct device *parent, struct device *self, void *args)
     94 {
     95 	struct gpiic_softc *sc = (struct gpiic_softc *)self;
     96 	struct opb_attach_args *oaa = args;
     97 	struct i2cbus_attach_args iba;
     98 
     99 	aprint_naive(": IIC controller\n");
    100 	aprint_normal(": On-Chip IIC controller\n");
    101 
    102 	sc->sc_bust = oaa->opb_bt;
    103 
    104 	bus_space_map(sc->sc_bust, oaa->opb_addr, IIC_NREG, 0, &sc->sc_bush);
    105 
    106 	lockinit(&sc->sc_buslock, PRIBIO|PCATCH, "gpiiclk", 0, 0);
    107 
    108 	sc->sc_txen = 0;
    109 	sc->sc_i2c.ic_cookie = sc;
    110 	sc->sc_i2c.ic_acquire_bus = gpiic_acquire_bus;
    111 	sc->sc_i2c.ic_release_bus = gpiic_release_bus;
    112 	sc->sc_i2c.ic_exec = NULL;
    113 	sc->sc_i2c.ic_send_start = gpiic_send_start;
    114 	sc->sc_i2c.ic_send_stop = gpiic_send_stop;
    115 	sc->sc_i2c.ic_initiate_xfer = gpiic_initiate_xfer;
    116 	sc->sc_i2c.ic_read_byte = gpiic_read_byte;
    117 	sc->sc_i2c.ic_write_byte = gpiic_write_byte;
    118 
    119 	sc->sc_bops.ibo_set_dir = gpiic_set_dir;
    120 	sc->sc_bops.ibo_set_bits = gpiic_set_bits;
    121 	sc->sc_bops.ibo_read_bits = gpiic_read_bits;
    122 	sc->sc_bops.ibo_bits[I2C_BIT_SDA] = IIC_DIRECTCNTL_SDAC;
    123 	sc->sc_bops.ibo_bits[I2C_BIT_SCL] = IIC_DIRECTCNTL_SCC;
    124 	sc->sc_bops.ibo_bits[I2C_BIT_OUTPUT] = 1;
    125 	sc->sc_bops.ibo_bits[I2C_BIT_INPUT] = 0;
    126 
    127 	/*
    128 	 * Put the controller into Soft Reset. This allows us to
    129 	 * manually bit-bang the I2C clock/data lines.
    130 	 */
    131 	bus_space_write_1(sc->sc_bust, sc->sc_bush, IIC_XTCNTLSS,
    132 	    IIC_XTCNTLSS_SRST);
    133 	delay(10);
    134 	bus_space_write_1(sc->sc_bust, sc->sc_bush, IIC_DIRECTCNTL,
    135 	    IIC_DIRECTCNTL_SCC | IIC_DIRECTCNTL_SDAC);
    136 
    137 	iba.iba_name = "iic";
    138 	iba.iba_tag = &sc->sc_i2c;
    139 	(void) config_found(&sc->sc_dev, &iba, iicbus_print);
    140 }
    141 
    142 static int
    143 gpiic_acquire_bus(void *arg, int flags)
    144 {
    145 	struct gpiic_softc *sc = arg;
    146 
    147 	if (flags & I2C_F_POLL)
    148 		return (0);
    149 
    150 	return (lockmgr(&sc->sc_buslock, LK_EXCLUSIVE, NULL));
    151 }
    152 
    153 static void
    154 gpiic_release_bus(void *arg, int flags)
    155 {
    156 	struct gpiic_softc *sc = arg;
    157 
    158 	if (flags & I2C_F_POLL)
    159 		return;
    160 
    161 	(void) lockmgr(&sc->sc_buslock, LK_RELEASE, NULL);
    162 }
    163 
    164 static int
    165 gpiic_send_start(void *arg, int flags)
    166 {
    167 	struct gpiic_softc *sc = arg;
    168 
    169 	return (i2c_bitbang_send_start(sc, flags, &sc->sc_bops));
    170 }
    171 
    172 static int
    173 gpiic_send_stop(void *arg, int flags)
    174 {
    175 	struct gpiic_softc *sc = arg;
    176 
    177 	return (i2c_bitbang_send_stop(sc, flags, &sc->sc_bops));
    178 }
    179 
    180 static int
    181 gpiic_initiate_xfer(void *arg, i2c_addr_t addr, int flags)
    182 {
    183 	struct gpiic_softc *sc = arg;
    184 
    185 	return (i2c_bitbang_initiate_xfer(sc, addr, flags, &sc->sc_bops));
    186 }
    187 
    188 static int
    189 gpiic_read_byte(void *arg, uint8_t *vp, int flags)
    190 {
    191 	struct gpiic_softc *sc = arg;
    192 
    193 	return (i2c_bitbang_read_byte(sc, vp, flags, &sc->sc_bops));
    194 }
    195 
    196 static int
    197 gpiic_write_byte(void *arg, uint8_t v, int flags)
    198 {
    199 	struct gpiic_softc *sc = arg;
    200 
    201 	return (i2c_bitbang_write_byte(sc, v, flags, &sc->sc_bops));
    202 }
    203 
    204 static void
    205 gpiic_set_dir(void *arg, uint32_t bits)
    206 {
    207 	struct gpiic_softc *sc = arg;
    208 
    209 	sc->sc_txen = (uint8_t)bits;
    210 }
    211 
    212 static void
    213 gpiic_set_bits(void *arg, uint32_t bits)
    214 {
    215 	struct gpiic_softc *sc = arg;
    216 
    217 	if (sc->sc_txen == 0 && (bits & IIC_DIRECTCNTL_SDAC) == 0) {
    218 		printf("gpiic_set_bits: SDA low with no output enable\n");
    219 		bits |= IIC_DIRECTCNTL_SDAC;
    220 	}
    221 
    222 	bus_space_write_1(sc->sc_bust, sc->sc_bush, IIC_DIRECTCNTL, bits);
    223 }
    224 
    225 static uint32_t
    226 gpiic_read_bits(void *arg)
    227 {
    228 	struct gpiic_softc *sc = arg;
    229 	uint8_t rv;
    230 
    231 	if (sc->sc_txen != 0)
    232 		printf("gpiic_read_bits: Read in output mode\n");
    233 
    234 	rv = bus_space_read_1(sc->sc_bust, sc->sc_bush, IIC_DIRECTCNTL) << 2;
    235 	rv &= (IIC_DIRECTCNTL_SCC | IIC_DIRECTCNTL_SDAC);
    236 
    237 	return ((uint32_t)rv);
    238 }
    239